虚拟语气用wouldn't好.
他很喜欢参加聚会,总是第一个到He loves parties very much and is always__the__ _first___ _to___ __come____
如果没有你的帮助,我不可能完成那项工作I __wouldn't___ have finished the work __without___ your help
另外可以说：
But for your help,I wouldn't have finished the work.